Risk Factors for Glaucoma Drainage Device Exposure in a Middle-Eastern Population

Anterior segment OCT for imaging PAUL® glaucoma implant patch grafts: a useful method for follow-up and risk management

AIM

To evaluate a useful, non-contact method for the follow-up of pericardium patch graft changes in patients undergoing PAUL® Glaucoma Implant (PGI) surgery using high-resolution anterior segment optical coherence tomography (OCT) to predict tube erosions.

METHODS

Prospective analysis over six months of tube pericardium patch graft thickness of PGI surgical cases at the University Eye Hospital Bonn, Germany, from November 2021 to August 2022. In all eyes, Tutopatch® (RTI Surgical, United States) pericardium was used to cover the implant intra-operatively. Anterior segment OCT (AS-OCT, Heidelberg ANTERION® Swept-Source-OCT) examinations were performed following a standardized protocol to measure quantitative and qualitative aspects of the patch grafts before surgery, and at three and six months after surgery.

RESULTS

Twenty-six eyes of 26 patients were included. Thickness of the patch material was 1188 µm (IQR 415 µm) directly after implantation and decreased over time to 1068 µm (IQR 478 µm) at 3 months and 846 µm (IQR 677 µm) at 6 months. No significant differences between groups were shown concerning gender (p = 0.128), ethnicity (p = 1.000), age (p = 0.741), glaucoma type (p = 0.173), other concurrent diseases (p = 0.302), former glaucoma surgeries (p = 1.000) and the quadrant of implantation (p = 0.555). Five eyes developed implant exposure. When comparing eyes with and without tube exposure, no significant differences were shown in average patch thickness above the tube directly after implantation (p = 0.476). However, significant differences in average thickness were observed at 3 months (p = 0.013) and 6 months (p = 0.005).

CONCLUSIONS

Pericardial patch grafts tend to thin over time which can be assessed by AS-OCT, the latter proving to be a useful method to follow-up patients who undergo patch graft implantation during PGI surgery. This investigation could potentially help identify patients at risk of tube exposure which in turn could lead to modification of patient management. It could also possibly be used in future studies to find more suitable patch materials.

Aqueous shunt exposure repair: outcomes and risk factors for recurrence

OBJECTIVE

To investigate the outcomes of aqueous shunt exposure repair and to identify risk factors for recurrent exposure after surgical repair.

METHODS

This is a retrospective interventional case series of consecutive patients who underwent repair of an exposed aqueous shunt. Demographic and clinical data were extracted from the patients' records and survival analysis was employed to determine the probability of survival of the repair without further exposure. Cox proportional regression analysis was utilised to identify potential risk factors for failure of the repair surgery.

RESULTS

Seventy-six eyes of 76 patients were included in the study. The probability of survival without further exposure was 76.2% (CI 66.9-86.8%), 72.7% (CI 62.8-84.1%) and 54.7% (40.5-73.7%) at 1,2 and 4 years, respectively. No eye in which the tube was repositioned in the anterior chamber or in the sulcus (n = 9; 11.8%) developed a recurrence of the exposure. A shorter interval from the time of tube insertion to the repair surgery (HR 2.87 [CI 1.11-7.39]; p = 0.03; reference longer interval), a history of previous surgical revision (HR 3.06 [1.15-8.12]; p = 0.02; reference no prior revision) and the use of a human pericardial donor patch at the time of revision (HR 3.43 [1.16-10.13]; p = 0.03; reference other than pericardium) was associated with an increased risk of exposure recurrence.

CONCLUSION

Aqueous shunt exposure revision is associated with reasonable mid and long term success. A shorter interval from tube insertion to exposure revision, previous revisions and the use of a human pericardium patch were associated with increased risk of failure.

Two-Year Clinical Outcomes of the PAUL Glaucoma Implant in White Patients With Refractory Glaucoma

PRCIS

This prospectively collected case series of 56 eyes having PAUL glaucoma implant (PGI) surgery is the first to demonstrate its medium-term safety and effectiveness in what is essentially an exclusively Caucasian population.

BACKGROUND

To report 2-year outcomes from a single-center cohort undergoing PGI surgery.

METHODS

Prospectively collected data on patients undergoing PGI surgery at the University Eye Hospital Bonn, Germany, from April 2021 to September 2021.

RESULTS

Of 53 patients, 56 eyes were included. Complete and qualified success rates (95% CI) were 52% (37-66) and 89% (80-96) for criterion A ( intraocular pressure [IOP]≤21 mm Hg), 48% (36-61) and 79% (67-88) for criterion B (IOP≤18 mm Hg), 45% (32-57) and 64% (52-77%) for criterion C (IOP≤15 mm Hg) and 27% (16-40) and 38% (25-50) for criterion D (IOP≤12 mm Hg), respectively. Mean IOP decreased from 25.43 mm Hg (7-48 mm Hg) to 11.25 mm Hg (3-24 mm Hg) (reduction of 50%) after 24 months with a reduction of IOP-lowering agents from 3.50 (1-5) to 0.46 (0-3). One eye needed an injection of viscoelastic due to significant hypotony with AC shallowing; 3 eyes received a Descemet membrane endothelial keratoplasty because of persistent corneal decompensation; 9 eyes developed tube exposure which required conjunctival revision with additional pericardial patch graft, with 5 of these eyes eventually needing tube explantation. An intraluminal prolene stent was removed in 24 eyes (42.9%) after a mean time period of 5.67 months (2-15 m). Mean IOP before removal was 21.4 mm Hg (12-40 mm Hg) and decreased to 11.15 mm Hg (6-20 mm Hg).

CONCLUSIONS

PGI surgery is an effective procedure for reducing IOP and pressure-lowering therapy. The use of an intraluminal prolene stent impedes hypotony in the early postoperative phase and enables further noninvasive IOP lowering during the postoperative course.

Evaluation of pericardium patch graft thickness in patients with Ahmed glaucoma valve implantation: an anterior segment OCT study

PURPOSE

To evaluate the changes in thickness of tissues, specifically the pericardium patch graft (PPG) covering the silicone tube in Ahmed Glaucoma Valve (AGV) surgery.

STUDY DESIGN

Prospective observational study.

METHODS

This study included cases with refractory glaucoma that underwent AGV implantation with PPG coverage. Conjunctival epithelium, stroma and PPG thickness covering the tube were measured using anterior segment optical coherence tomography (AS-OCT) at 1, 6 and 12 months. Additionally, the same measurements were taken 1500 µm away from the tube as a control for the central measurements.

RESULTS

Twenty-seven eyes of 27 patients were evaluated in the study. Although PPG thickness decreased significantly in both regions, the amount of reduction was more pronounced centrally. Centrally, the reduction rate was 21.2% and 34.8% during the 1-6 months period and 6-12 months period, while peripherally it was 3.5% and 5.1%, respectively. No change was observed in the thickness of the epithelium during the follow-up period. There was a significant thinning of the stroma in the central and peripheral regions during the 1-6 months period (30.5% and 17%, respectively). No cases of exposure were observed during the follow-up period.

CONCLUSION

Although the most evident thinning of the layers covering the tube was observed in the early postoperative period, PPG showed a stable decrease even in the late period. The progressive reduction in the PPG thickness observed also in the peripheral region indicates that factors beyond mechanical forces contribute to this degenerative process. AS-OCT could be a valuable non-invasive tool in clarifying this process.

Five-Year Outcomes of Graft-Free Tube Shunts and Risk Factors for Tube Exposures in Glaucoma

PRCIS

Use of a scleral tunnel technique instead of a patch graft can be considered in most cases of tube shunt implantation. Grafts may still be considered in younger (<65 y old) East Asians.

PURPOSE

(1) To assess the risk factors for tube exposure with a graft-free implantation technique and (2) to examine 5-year outcomes of graft-free tube shunt insertion.

METHODS

This was a retrospective case series of 204 consecutive eyes undergoing a glaucoma tube shunt implantation with a scleral tunnel technique in lieu of a graft. Preoperative and postoperative best-corrected visual acuity, intraocular pressure, and number of glaucoma medications were compared. Failure was defined as the following: (1) intraocular pressure >21 mm Hg or ≤5 mm Hg on 2 consecutive visits after 3 mo; (2) required additional glaucoma surgery; (3) loss of light perception. Univariable and multivariable regression analyses were conducted to identify risk factors of tube exposures.

RESULTS

Intraocular pressure and the number of glaucoma medications were significantly decreased at all postoperative time points ( P <0.001). Success rates were 91% at year 1, 75% at year 3, and 67% at year 5. The most common early (<3 mo) complication was tube malpositioning. The most common late (>3 mo to 5 y) complications were corneal complications and uncontrolled intraocular pressure. By year 5, 6.9% of tubes were exposed. Multivariable regression showed that age less than 65 years old (odds ratio: 3.66, P =0.04) and East Asian ethnicity (odds ratio: 3.36, P =0.04) were associated with significantly increased risk of tube exposure.

CONCLUSIONS

Graft-free glaucoma tube implantation has comparable long-term outcomes and complication rates to shunts with a graft. Younger (<65 y old) East Asians are at greater risk of tube exposure without a graft.

Risk Factors for Glaucoma Drainage Device Exposure in Children: A Case-Control Study

PURPOSE

To identify the risk factors for glaucoma drainage device (GDD) exposure in children.

DESIGN

Retrospective case-control study.

METHODS

The study population comprised children (one eye each) who presented with a history of GDD exposure to a tertiary care eye hospital over the period January 2014 to January 2020. Consecutive children (age <18 years) were included. A control group from the same time period (children without GDD exposure) were included in the ratio of 5 controls to every 1 case of exposure. The main outcome measures included risk factors for exposure (univariate and multivariate analysis).

RESULTS

A total of 21 eyes (of 21 children with implant exposure) and 115 eyes (of 115 children without exposure) were included in this study. During the same study period, a total of 494 eyes had undergone GDD implantation, giving an estimated incidence of exposure of 4.25%). In the bivariate analysis, GDD exposure was associated with multiple previous ocular surgeries (P = .001), longer follow-up duration (P < .001), combined procedure at the time of primary implantation (P = .002), and a younger age at the time of primary implantation (P = .006). The former 3 risk factors continued to prove a statistically significant association on multivariable regression analysis. Postoperative use of eye lubricants was more common among children in the control group (P = .007).

CONCLUSION

In pediatric glaucoma patients, younger age and combined procedure at the time of primary GDD implantation, in addition to multiple previous ocular surgeries, were associated with greater risk of implant exposure. Postoperative use of eye lubricants may be protective.

Risk Factors for Glaucoma Drainage Device Revision or Removal Using the IRIS Registry

PURPOSE

To elucidate risk factors for revision or removal of glaucoma drainage devices (GDD) in glaucoma patients in the United States.

DESIGN

Retrospective cohort study.

METHODS

IRIS Registry (Intelligent Research in Sight) patients who underwent GDD insertion between January 1, 2013 and December 31, 2018 were included. Various demographic and clinical factors were collected. Kaplan-Meier survival plots, Cox proportional-hazard models utilizing Firth's Penalized Likelihood, and multivariate linear regression models were used. The main outcome measures were hazard ratios (HR) and beta coefficient (β) estimates.

RESULTS

A total of 44,330 distinct patients underwent at least 1 GDD implantation, and 3354 of these underwent subsequent GDD revision or removal surgery. With failure defined as GDD revision/removal, factors significantly associated with decreased failure included unknown race (HR = 0.83; P = .004) and unknown ethnicity (HR = 0.68; P < .001). Factors associated with increased risk of GDD revision/removal surgery included presence of chronic angle-closure glaucoma (HR = 1.32; P < .001) and dry eye disease (HR = 1.30; P = .007). Additionally, factors associated with a decreased average time (in days) to GDD revision/removal included male sex (β = -25.96; P = .044), unknown race (β = -55.28; P = .013), and right-eye laterality (β = -38.67; P = .026). Factors associated with an increased average time to GDD revision/removal included having a history of a past eye procedure (β = 104.83; P < .001) and being an active smoker (β = 38.15; P = .024).

CONCLUSIONS

The size and scope of the IRIS Registry allows for detection of subtle associations between risk factors and GDD revision or removal surgery. The aforementioned demographic and clinical factors may all have an impact on GDD longevity and can inform the treatment options available for glaucoma patients.

Preliminary Surgical Outcomes of a Trimmed-Plate Aurolab Aqueous Drainage Implant (AADI) in Eyes at High Risk of Hypotony

Purpose

We describe the technique of trimming the 350 mm² AADI glaucoma shunt plate and report preliminary results that test the hypothesis that the IOP-lowering efficacy of the trimmed AADI glaucoma shunt is comparable to the Baerveldt 250 mm² glaucoma drainage implant with a comparable safety profile to the standard AADI implant.

Methods

Consecutive patients who had received the modified trimmed-plate AADI, standard AADI and Baerveldt 250 mm² were included in the study. This included patients with refractory or primary or secondary glaucoma of all ages and eyes with and without previous glaucoma surgery. The decision for trimming the AADI plate was made according to the surgeon’s perceived risk of hypotony. Pre-operative, intraoperative and post-operative data were collected from the hospital electronic medical record system. Surgical success was defined as IOP ≥5 mmHg and ≤21 mmHg on two consecutive visits after 3 months, whilst maintaining at least LP vision and avoiding re-operation for glaucoma.

Results

The sample consisted of 69 eyes (19 with trimmed-plate AADI implant; 36 eyes with the standard AADI implant and 14 eyes who received a BGI-250). The mean IOP reduction at 1 year was 15 mmHg for the Baerveldt-250, 10 mmHg for the AADI and 13 mmHg for the trimmed-plate AADI. The surgical success rate of the implants over 1 year was 85.7% (95% CI, 53.9–96.2%) for BGI-250, 81.5% (62.6–91.5%) for standard AADI and 78.2% (51.7–91.3%) for the trimmed AADI.

Conclusion

Trimming the plate of the AADI manually may provide a safe and low-cost method of obtaining a successful surgical outcome in eyes at high risk of hypotony.

Tube Revision Outcomes for Exposure with Different Repair Techniques

Purpose

The aim of this study was to report our experience with eyes that presented with an initial GDD exposure and their subsequent outcome in terms of re-exposure.

Methods

A retrospective review of charts of 42 patients (43 eyes) who presented with a GDD exposure during the period 2008–2015 in a tertiary eye care center was performed. Demographic data, past ocular history, pre-operative and post-operative information including the surgical technique of GDD surgery and exposure repair were recorded. The patients were followed for further exposure to the date of the last follow-up clinic visit. For each type of repair technique, details were collected on risk and timing of GDD exposure. The baseline features of eyes that had further exposure after initial exposure were compared to eyes without further exposure.

Results

Forty-three eyes were identified which had repair after an initial exposure. The mean ± SD age was 54 ± 27 years. Of the GDDs, Ahmed FP7 was performed in 31 eyes, Ahmed FP8 in two eyes, Ahmed S2 in five eyes, Krupin valve in two eyes and Baerveldt 350 GDD in three eyes. The methods of repair and the relative risk [95% CI] of re-exposure were: conjunctival closure only (n=4; RR=2.10 [0.84–5.23]); repair with patch graft and conjunctival repair (n=18), RR=1.24 [0.51–3.01]; tube repositioning, use of patch graft and conjunctival repair (n=14), RR=1.0; tube removal with replacement in a different quadrant, patch graft and conjunctival repair (n=3), RR=1.87 [0.64–5.48]. After the first exposure, 18 eyes had a second re-exposure, four eyes had a third re-exposure, and 1 eye had a fourth exposure.

Conclusions

The GDD exposure rates at our institution are consistent with other reports. Lack of a patch graft for repair is associated with a two-fold risk of subsequent re-exposure.

Outcome of Surgical Management of Glaucoma Following Complex Retinal Detachment Repair With Silicone Oil Tamponade: Drainage Implant Versus Cyclophotocoagulation

PRéCIS:: Glaucoma drainage devices (GDDs) are effective for the management of silicone oil-induced glaucoma. Although cyclophotocoagulation (CPC) has the advantage of shorter operative time and repeatability, it carries a higher risk of failure, blindness, and phthisis.

BACKGROUND/AIMS

To compare the surgical outcome of GDD implantation and diode laser CPC in the management of refractory glaucoma following vitrectomy with silicone oil (SO) injection.

MATERIALS AND METHODS

In total, 56 eyes with refractory glaucoma after SO tamponade that underwent either CPC or GDD implantation were retrospectively evaluated. All patients underwent a complete ophthalmic examination and intraocular pressure (IOP) measurement at baseline and 1 day, 1 week, 1, 3, 6, and 12 months postoperatively. The rates of complete success and qualified success (for IOP between ≥5 and ≤21 mm Hg) were analyzed.

RESULTS

A total of 17 eyes underwent GDD implantation and 39 eyes underwent CPC. The preoperative IOP was 35.7±7.9 mm Hg and 27.8±8.4 mm Hg for the CPC and GDD groups, respectively (P=0.001), with a worse baseline visual acuity (P=0.01) and a higher proportion of SO-filled eyes in the CPC group (P<0.01). The IOP at 1 year postoperatively was 23.5±11.5 mm Hg and 15.3±5.9 mm Hg for the CPC and GDD group, respectively (P=0.01). Both groups achieved a reduction in IOP and number of medications at 1 year (P<0.001). The success rate in the GDD group was 94.1% (16/17), and 53.8% (21/39) in the CPC group at 12 months (P<0.005). Five eyes and 1 eye lost light perception vision in the CPC and GDD groups, respectively.

CONCLUSIONS

GDD implantation may carry a higher surgical success rate than CPC. However, CPC retains the advantage of being technically easier and repeatable.